5-Iodo-2-aminopyridine

Thus, reaction of 3-chloro-, 3-bromo- and 3-iodo-pyridine with potassium amide in liquid ammonia give in each case the same mixture of 3- and 4-aminopyridine, showing the intermediacy of... 

An interesting double amination of 2-chloro-3-iodo-pyridine (16) with 2-aminopyridine (17) catalyzed by Pd/BINAP or Pd/Xantphos, which gives dipyridoimidazoles (18), was described by B. U. W. Maes and co-workers. 2-Aminopyrazine was also found to be a capable coupling partner.70 The mechanism is most likely an initial amination at the 3-iodo position followed by an intramolecular amination at the 2-chloro position. 

Fig. 11-1. Intramolecular electronic effects in the adsorption of meta- and para-% ih-stituted pyridines on (a) alumina and (b) silica (15,24). 1, 4-amino 2, 3, 4-dimethyl 3, 4-methyl 4, 4-ethyl 5, 3-methyl 6, pyridine 7, 3-hydroxy 8, 4-chloro 9. 4-aldehyde 10,3-acetyl 11,3-iodo 12,3-aldehyde 13, 3-chloro 14, 3-bromo 15. 4-cyano 16, 3-cyano 17, 3,5-dichloro. [The plots do not include points for the compound 3-aminopyridine see discussion of Ref (/5).]...

Metal-acid solutions have been employed in the reduction of nitropyridines to aminopyridines. Zinc dust and acetic acid have been used in the preparation of 3-amino-l-benzyl-4-pyridone or 3-amino-l-benzyl-S-iodo-4-pyridone from the corresponding 3-nitro derivatives. Tin or iron in acids is more popular. For example, 3-amino-2-(o-bromobenzyloxy)-pyridine is obtained by the reduction of 2-(o-bromobenzyloxy)-3-nitropyridine using iron and hydrochloric acid. Various ferrous salts have also been effective reducing agents. Several derivatives of phenyl 5-amino-2-pyridyl sulfide (K-16) (or the sulfone)are... 

Chloro- and bromoaminopyridines are oxidized by persulfuric acid at 0° to their nitro derivatives thus, 3-chloro-, and 3-bromo-4-aminopyridine are converted to the respective 3-halo-4-nitropyridines. However, 4-araino-3-iodo-pyridine is not oxidized under these conditions. 4-Amino-2,3,5,6-tetrafluoro-pyridine is difficult to oxidize and requires refluxing peroxytrifiuoroacetic acid for 22 hours in order to yield the 4-nitro derivative. Potassium bromate has been used to oxidize S-amino-3-methyl-2-pyridone, but the product was not a nitro compound instead 3-hydroxy-6-methyl-2-aza-l,4-benzoquinone-4-(2,6-di-hydroxy-5-methyl-3-pyridyl)imine (IX-S7) was obtained. ... 

Innovanamine (2-methyl-l-8-D-glucopyranosyl-4-pyridone), hydrolysis of, 855 isolated from Bvodiopanax innovans, 855 preparation from a natural maltol glucoside, 855 3-Iodo-4-aminopyridine, 49 N-(4-Iodobutyl) -4-pyridone, polymer formed in water,... 

Two other modifications of the preparation of 2- and 4-halogenopyridines from amines have been used. 2-Aminopyridines, when treated with sodium ethoxide and amyl nitrite, give diazotates which have been converted by reaction with acids into 2-chloro-, -bromo- and -iodo-pyridinesi 4-Nitraminopyridine, with sodium nitrite in concentrated hydrochloric acid,... 

Aminopyridine 1-oxide has been diazotized and, by use of the Sandmeyer reaction, converted into 4-chloro- and 4-bromo-pyridine l-oxide" . 4-Iodo-pyridine 1-oxides have also been prepared through the diazonium reac-tion i . 

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